The number of given orbitals which have electron density along the axis is _________

$\mathrm{p_x,p_y,p_z,d_{xy},d_{yz},d_{xz},d_{z^2},d_{x^2-y^2}}$

The minimum uncertainty in the speed of an electron in an one dimensional region of length $2 \mathrm{a}_{\mathrm{o}}$ (Where $\mathrm{a}_{\mathrm{o}}=$ Bohr radius ) is _________ .

Based on Heisenberg's uncertainty principle, the uncertainty in the velocity of the electron to be found within an atomic nucleus of diameter $10^{-15} \mathrm{~m}$ is ________ $\times 10^9 \mathrm{~ms}^{-1}$ (nearest integer)

Consider an imaginary ion ${ }_{22}^{48} \mathrm{X}^{3-}$. The nucleus contains ''% more neutrons than the number of electrons in the ion. The value of 'a' is _______________. [nearest integer]

The number of atomic orbitals from the following having 5 radial nodes is ___________.

$7 \mathrm{s}, 7 \mathrm{p}, 6 \mathrm{s}, 8 \mathrm{p}, 8 \mathrm{d}$

The de-Broglie's wavelength of an electron in the $4^{\text {th }}$ orbit is ________ $\pi \mathrm{a}_0$. ( Bohr's radius)

If the uncertainty in velocity and position of a minute particle in space are, 2.4 $\times$ 10^$-$26 (m s^$-$1) and 10 (m) respectively. The mass of the particle in g is ____________. (Nearest integer)

The wavelength of an electron and a neutron will become equal when the velocity of the electron is $x$ times the velocity of neutron. The value of $x$ is ____________. (Nearest Integer)

(Mass of electron is $9.1 \times 10^{-31} \mathrm{~kg}$ and mass of neutron is )

If wavelength of the first line of the Paschen series of hydrogen atom is 720 nm, then the wavelength of the second line of this series is _________ nm. (Nearest integer)

For hydrogen atom, energy of an electron in first excited state is $-3.4 \mathrm{~eV}, \mathrm{K} . \mathrm{E}$. of the same electron of hydrogen atom is $x \mathrm{~eV}$. Value of is _________ . (Nearest integer)

Electrons in a cathode ray tube have been emitted with a velocity of 1000 m s$^{-1}$. The number of following statements which is/are $\underline {\mathrm{true}}$ about the emitted radiation is ____________.

Frequency of the de-Broglie wave of electron in Bohr's first orbit of hydrogen atom is _________ $\times 10^{13} \mathrm{~Hz}$ (nearest integer).

[Given : $\mathrm{R}_{\mathrm{H}}$ (Rydberg constant) (Plank's constant) .]

If the $x$-intercept of a focal chord of the parabola $y^{2}=8x+4y+4$ is 3, then the length of this chord is equal to ____________.

The longest wavelength of light that can be used for the ionisation of lithium atom (Li) in its ground state is x $\times$ 10^$-$8 m. The value of x is ___________. (Nearest Integer).

(Given : Energy of the electron in the first shell of the hydrogen atom is $-$2.2 10 ms)

The orbital angular momentum of an electron in $3 \mathrm{~s}$ orbital is $\frac{x h}{2 \pi}$. The value of is ____________ (nearest integer)